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Barricklow J, Blatnik M. 2-Arachidonoylglycerol is a substrate for butyrylcholinesterase: A potential mechanism for extracellular endocannabinoid regulation. Arch Biochem Biophys 2013; 536:1-5. [PMID: 23689009 DOI: 10.1016/j.abb.2013.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/02/2013] [Accepted: 05/05/2013] [Indexed: 11/25/2022]
Abstract
2-Arachidonoylglycerol (2-AG) is a component of the endocannabinoid receptor pathway and is primarily hydrolyzed by monoacylglycerol lipase (MAGL) in vivo. We found that the non-specific serine esterase, butyrylcholinesterase (BChE), can hydrolyze 2-AG with reasonable affinity and may present a new compensatory mechanism for endocannabinoid regulation. In vitro hydrolysis reactions of 2-AG with equine BChE were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) positive/negative electrospray ionization (ESI±) to measure the formation of arachidonic acid (AA) and the loss of 2-AG over time (min). The resulting Michaelis-Menten approximations reveal that BChE has affinity towards 2-AG in phosphate buffer at neutral pH (7.4). The calculated Vmax, Km and kcat were 12.1nmols(-1), 57.5μM, and 0.074s(-1), respectively, which produced a diffusion-controlled rate of association (kcat/Km) of 1.3×10(3)M(-1)s(-1). Human BChE 2-AG hydrolysis was measured by immunoprecipitating BChE from fresh plasma and monitoring 2-AG loss and AA formation over time. These findings show that BChE can hydrolyze 2-AG which may be evidence of a more specific role for BChE in endocannabinoid regulation.
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Affiliation(s)
- Jason Barricklow
- Pfizer Global Research and Development, Groton Laboratories, 558 Eastern Point Rd., Groton, CT 06340, USA
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52
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Starowicz K, Makuch W, Korostynski M, Malek N, Slezak M, Zychowska M, Petrosino S, De Petrocellis L, Cristino L, Przewlocka B, Di Marzo V. Full inhibition of spinal FAAH leads to TRPV1-mediated analgesic effects in neuropathic rats and possible lipoxygenase-mediated remodeling of anandamide metabolism. PLoS One 2013; 8:e60040. [PMID: 23573230 PMCID: PMC3616060 DOI: 10.1371/journal.pone.0060040] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 02/20/2013] [Indexed: 01/10/2023] Open
Abstract
Neuropathic pain elevates spinal anandamide (AEA) levels in a way further increased when URB597, an inhibitor of AEA hydrolysis by fatty acid amide hydrolase (FAAH), is injected intrathecally. Spinal AEA reduces neuropathic pain by acting at both cannabinoid CB1 receptors and transient receptor potential vanilloid-1 (TRPV1) channels. Yet, intrathecal URB597 is only partially effective at counteracting neuropathic pain. We investigated the effect of high doses of intrathecal URB597 on allodynia and hyperalgesia in rats with chronic constriction injury (CCI) of the sciatic nerve. Among those tested, the 200 µg/rat dose of URB597 was the only one that elevated the levels of the FAAH non-endocannabinoid and anti-inflammatory substrates, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), and of the endocannabinoid FAAH substrate, 2-arachidonoylglycerol, and fully inhibited thermal and tactile nociception, although in a manner blocked almost uniquely by TRPV1 antagonism. Surprisingly, this dose of URB597 decreased spinal AEA levels. RT-qPCR and western blot analyses demonstrated altered spinal expression of lipoxygenases (LOX), and baicalein, an inhibitor of 12/15-LOX, significantly reduced URB597 analgesic effects, suggesting the occurrence of alternative pathways of AEA metabolism. Using immunofluorescence techniques, FAAH, 15-LOX and TRPV1 were found to co-localize in dorsal spinal horn neurons of CCI rats. Finally, 15-hydroxy-AEA, a 15-LOX derivative of AEA, potently and efficaciously activated the rat recombinant TRPV1 channel. We suggest that intrathecally injected URB597 at full analgesic efficacy unmasks a secondary route of AEA metabolism via 15-LOX with possible formation of 15-hydroxy-AEA, which, together with OEA and PEA, may contribute at producing TRPV1-mediated analgesia in CCI rats.
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Affiliation(s)
- Katarzyna Starowicz
- Dept. of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna, Krakow, Poland
| | - Wioletta Makuch
- Dept. of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna, Krakow, Poland
| | - Michal Korostynski
- Dept. of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna, Krakow, Poland
| | - Natalia Malek
- Dept. of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna, Krakow, Poland
| | - Michal Slezak
- Dept. of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna, Krakow, Poland
| | - Magdalena Zychowska
- Dept. of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna, Krakow, Poland
| | - Stefania Petrosino
- Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, CNR, Pozzuoli (Naples), Italy
| | | | - Luigia Cristino
- Endocannabinoid Research Group, Istituto di Cibernetica, CNR, Pozzuoli (Naples), Italy
| | - Barbara Przewlocka
- Dept. of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna, Krakow, Poland
| | - Vincenzo Di Marzo
- Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, CNR, Pozzuoli (Naples), Italy
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Endogenous cannabinoids revisited: A biochemistry perspective. Prostaglandins Other Lipid Mediat 2013; 102-103:13-30. [DOI: 10.1016/j.prostaglandins.2013.02.002] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 02/20/2013] [Accepted: 02/21/2013] [Indexed: 12/13/2022]
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Ueda N, Tsuboi K, Uyama T. Metabolism of endocannabinoids and related N-acylethanolamines: canonical and alternative pathways. FEBS J 2013; 280:1874-94. [PMID: 23425575 DOI: 10.1111/febs.12152] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 01/14/2013] [Accepted: 01/23/2013] [Indexed: 12/31/2022]
Abstract
Endocannabinoids are endogenous ligands of the cannabinoid receptors CB1 and CB2. Two arachidonic acid derivatives, arachidonoylethanolamide (anandamide) and 2-arachidonoylglycerol, are considered to be physiologically important endocannabinoids. In the known metabolic pathway in mammals, anandamide and other bioactive N-acylethanolamines, such as palmitoylethanolamide and oleoylethanolamide, are biosynthesized from glycerophospholipids by a combination of Ca(2+)-dependent N-acyltransferase and N-acyl-phosphatidylethanolamine-hydrolyzing phospholipase D, and are degraded by fatty acid amide hydrolase. However, recent studies have shown the involvement of other enzymes and pathways, which include the members of the tumor suppressor HRASLS family (the phospholipase A/acyltransferase family) functioning as Ca(2+)-independent N-acyltransferases, N-acyl-phosphatidylethanolamine-hydrolyzing phospholipaseD-independent multistep pathways via N-acylated lysophospholipid, and N-acylethanolamine-hydrolyzing acid amidase, a lysosomal enzyme that preferentially hydrolyzes palmitoylethanolamide. Although their physiological significance is poorly understood, these new enzymes/pathways may serve as novel targets for the development of therapeutic drugs. For example, selective N-acylethanolamine-hydrolyzing acid amidase inhibitors are expected to be new anti-inflammatory and analgesic drugs. In this minireview, we focus on advances in the understanding of these enzymes/pathways. In addition, recent findings on 2-arachidonoylglycerol metabolism are described.
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Affiliation(s)
- Natsuo Ueda
- Department of Biochemistry, Kagawa University School of Medicine, Miki, Kagawa, Japan.
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55
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Zogopoulos P, Vasileiou I, Patsouris E, Theocharis S. The neuroprotective role of endocannabinoids against chemical-induced injury and other adverse effects. J Appl Toxicol 2013; 33:246-64. [DOI: 10.1002/jat.2828] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 08/31/2012] [Accepted: 09/01/2012] [Indexed: 12/21/2022]
Affiliation(s)
- Panagiotis Zogopoulos
- 1st Department of Pathology, Medical School; National and Kapodistrian University of Athens; Athens; Greece
| | - Ioanna Vasileiou
- 1st Department of Pathology, Medical School; National and Kapodistrian University of Athens; Athens; Greece
| | - Efstratios Patsouris
- 1st Department of Pathology, Medical School; National and Kapodistrian University of Athens; Athens; Greece
| | - Stamatios Theocharis
- 1st Department of Pathology, Medical School; National and Kapodistrian University of Athens; Athens; Greece
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56
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Zogopoulos P, Vasileiou I, Patsouris E, Theocharis SE. The role of endocannabinoids in pain modulation. Fundam Clin Pharmacol 2013; 27:64-80. [PMID: 23278562 DOI: 10.1111/fcp.12008] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 09/03/2012] [Accepted: 09/21/2012] [Indexed: 12/16/2022]
Abstract
The endocannabinoid system (ES) is comprised of cannabinoid (CB) receptors, their endogenous ligands (endocannabinoids), and proteins responsible for their metabolism. Endocannabinoids serve as retrograde signaling messengers in GABAergic and glutamatergic synapses, as well as modulators of postsynaptic transmission, that interact with other neurotransmitters. Physiological stimuli and pathological conditions lead to differential increases in brain endocannabinoids that regulate distinct biological functions. Furthermore, endocannabinoids modulate neuronal, glial, and endothelial cell function and exert neuromodulatory, anti-excitotoxic, anti-inflammatory, and vasodilatory effects. Analgesia is one of the principal therapeutic targets of cannabinoids. Cannabinoid analgesia is based on the suppression of spinal and thalamic nociceptive neurons, but peripheral sites of action have also been identified. The chronic pain that occasionally follows peripheral nerve injury differs fundamentally from inflammatory pain and is an area of considerable unmet therapeutic need. Over the last years, considerable progress has been made in understanding the role of the ES in the modulation of pain. Endocannabinoids have been shown to behave as analgesics in models of both acute nociception and clinical pain such as inflammation and painful neuropathy. The framework for such analgesic effects exists in the CB receptors, which are found in areas of the nervous system important for pain processing and in immune cells that regulate the neuro-immune interactions that mediate the inflammatory hyperalgesia. The purpose of this review is to present the available research and clinical data, up to date, regarding the ES and its role in pain modulation, as well as its possible therapeutic perspectives.
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Affiliation(s)
- Panagiotis Zogopoulos
- First Department of Pathology, Medical School, University of Athens, Goudi, Athens, Greece
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57
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Fonseca BM, Correia-da-Silva G, Almada M, Costa MA, Teixeira NA. The Endocannabinoid System in the Postimplantation Period: A Role during Decidualization and Placentation. Int J Endocrinol 2013; 2013:510540. [PMID: 24228028 PMCID: PMC3818851 DOI: 10.1155/2013/510540] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 09/04/2013] [Indexed: 01/08/2023] Open
Abstract
Although the detrimental effects of cannabis consumption during gestation are known for years, the vast majority of studies established a link between cannabis consumption and foetal development. The complex maternal-foetal interrelationships within the placental bed are essential for normal pregnancy, and decidua definitively contributes to the success of this process. Nevertheless, the molecular signalling network that coordinates strategies for successful decidualization and placentation are not well understood. The discovery of the endocannabinoid system highlighted new signalling mediators in various physiological processes, including reproduction. It is known that endocannabinoids present regulatory functions during blastocyst development, oviductal transport, and implantation. In addition, all the endocannabinoid machinery was found to be expressed in decidual and placental tissues. Additionally, endocannabinoid's plasmatic levels were found to fluctuate during normal gestation and to induce decidual cell death and disturb normal placental development. Moreover, aberrant endocannabinoid signalling during the period of placental development has been associated with pregnancy disorders. It indicates the existence of a possible regulatory role for these molecules during decidualization and placentation processes, which are known to be particularly vulnerable. In this review, the influence of the endocannabinoid system in these critical processes is explored and discussed.
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Affiliation(s)
- B. M. Fonseca
- Biologia da Inflamação e Reprodução, Instituto de Biologia Molecular e Celular (IBMC), Rua do Campo Alegre No. 823, 4150-180 Porto, Portugal
- Laboratório de Bioquímica, Departamento Ciências Biológicas, Faculdade de Farmácia da Universidade do Porto, Ciências Biológicas Rua de Jorge Viterbo Ferreira No. 228, 4050-313 Porto, Portugal
| | - G. Correia-da-Silva
- Biologia da Inflamação e Reprodução, Instituto de Biologia Molecular e Celular (IBMC), Rua do Campo Alegre No. 823, 4150-180 Porto, Portugal
- Laboratório de Bioquímica, Departamento Ciências Biológicas, Faculdade de Farmácia da Universidade do Porto, Ciências Biológicas Rua de Jorge Viterbo Ferreira No. 228, 4050-313 Porto, Portugal
| | - M. Almada
- Biologia da Inflamação e Reprodução, Instituto de Biologia Molecular e Celular (IBMC), Rua do Campo Alegre No. 823, 4150-180 Porto, Portugal
- Laboratório de Bioquímica, Departamento Ciências Biológicas, Faculdade de Farmácia da Universidade do Porto, Ciências Biológicas Rua de Jorge Viterbo Ferreira No. 228, 4050-313 Porto, Portugal
| | - M. A. Costa
- Biologia da Inflamação e Reprodução, Instituto de Biologia Molecular e Celular (IBMC), Rua do Campo Alegre No. 823, 4150-180 Porto, Portugal
- Laboratório de Bioquímica, Departamento Ciências Biológicas, Faculdade de Farmácia da Universidade do Porto, Ciências Biológicas Rua de Jorge Viterbo Ferreira No. 228, 4050-313 Porto, Portugal
| | - N. A. Teixeira
- Biologia da Inflamação e Reprodução, Instituto de Biologia Molecular e Celular (IBMC), Rua do Campo Alegre No. 823, 4150-180 Porto, Portugal
- Laboratório de Bioquímica, Departamento Ciências Biológicas, Faculdade de Farmácia da Universidade do Porto, Ciências Biológicas Rua de Jorge Viterbo Ferreira No. 228, 4050-313 Porto, Portugal
- *N. A. Teixeira:
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58
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Abstract
The endocannabinoid (eCB) system is involved in processes as diverse as control of appetite, perception of pain and the limitation of cancer cell growth and invasion. The enzymes responsible for eCB breakdown are attractive pharmacological targets, and fatty acid amide hydrolase inhibitors, which potentiate the levels of the eCB anandamide, are now undergoing pharmaceutical development. 'Drugable' selective inhibitors of monoacylglycerol lipase, a key enzyme regulating the levels of the other main eCB, 2-arachidonoylglycerol, were however not identified until very recently. Their availability has resulted in a large expansion of our knowledge concerning the pharmacological consequences of monoacylglycerol lipase inhibition and hence the role(s) played by the enzyme in the body. In this review, the pharmacology of monoacylglycerol lipase will be discussed, together with an analysis of the therapeutic potential of monoacylglycerol lipase inhibitors as analgesics and anticancer agents.
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Affiliation(s)
- C J Fowler
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Sweden.
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59
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Schicho R, Storr M. Targeting the endocannabinoid system for gastrointestinal diseases: future therapeutic strategies. Expert Rev Clin Pharmacol 2012; 3:193-207. [PMID: 22111567 DOI: 10.1586/ecp.09.62] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cannabinoids extracted from the marijuana plant (Cannabis sativa) and synthetic cannabinoids have numerous effects on gastrointestinal (GI) functions. Recent experimental data support an important role for cannabinoids in GI diseases. Genetic studies in humans have proven that defects in endocannabinoid metabolism underlie functional GI disorders. Mammalian cells have machinery, the so-called endocannabinoid system (ECS), to produce and metabolize their own cannabinoids in order to control homeostasis of the gut in a rapidly adapting manner. Pharmacological manipulation of the ECS by cannabinoids, or by drugs that raise the levels of endogenous cannabinoids, have shown beneficial effects on GI pathophysiology. This review gives an introduction into the functions of the ECS in the GI tract, highlights the role of the ECS in GI diseases and addresses its potential pharmacological exploitation.
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Affiliation(s)
- Rudolf Schicho
- Division of Gastroenterology, Department of Medicine, University of Calgary, 6D25, TRW Building, 3280 Hospital Drive NW, Calgary T2N 4N1, AB, Canada.
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60
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Fowler CJ, Björklund E, Lichtman AH, Naidu PS, Congiu C, Onnis V. Inhibitory properties of ibuprofen and its amide analogues towards the hydrolysis and cyclooxygenation of the endocannabinoid anandamide. J Enzyme Inhib Med Chem 2012; 28:172-82. [PMID: 22225576 DOI: 10.3109/14756366.2011.643304] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A dual-action cyclooxygenase (COX)-fatty acid amide hydrolase (FAAH) inhibitor may have therapeutic usefulness as an analgesic, but a key issue is finding the right balance of inhibitory effects. This can be done by the design of compounds exhibiting different FAAH/COX-inhibitory potencies. In the present study, eight ibuprofen analogues were investigated. Ibuprofen (1), 2-(4-Isobutylphenyl)-N-(2-(3-methylpyridin-2-ylamino)-2-oxoethyl)propanamide (9) and N-(3-methylpyridin-2-yl)-2-(4'-isobutylphenyl)propionamide (2) inhibited FAAH with IC(50) values of 134, 3.6 and 0.52 µM respectively. The corresponding values for COX-1 were ~29, ~50 and ~60 µM, respectively. Using arachidonic acid as substrate, the compounds were weak inhibitors of COX-2. However, when anandamide was used as COX-2 substrate, potency increased, with approximate IC(50) values of ~6, ~10 and ~19 µM, respectively. Compound 2 was confirmed to be active in vivo in a murine model of visceral nociception, but the effects of the compound were not blocked by CB receptor antagonists.
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Affiliation(s)
- Christopher J Fowler
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden.
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61
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Nomura DK, Lombardi DP, Chang JW, Niessen S, Ward AM, Long JZ, Hoover HH, Cravatt BF. Monoacylglycerol lipase exerts dual control over endocannabinoid and fatty acid pathways to support prostate cancer. ACTA ACUST UNITED AC 2011; 18:846-56. [PMID: 21802006 DOI: 10.1016/j.chembiol.2011.05.009] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 05/16/2011] [Accepted: 05/20/2011] [Indexed: 12/31/2022]
Abstract
Cancer cells couple heightened lipogenesis with lipolysis to produce fatty acid networks that support malignancy. Monoacylglycerol lipase (MAGL) plays a principal role in this process by converting monoglycerides, including the endocannabinoid 2-arachidonoylglycerol (2-AG), to free fatty acids. Here, we show that MAGL is elevated in androgen-independent versus androgen-dependent human prostate cancer cell lines, and that pharmacological or RNA-interference disruption of this enzyme impairs prostate cancer aggressiveness. These effects were partially reversed by treatment with fatty acids or a cannabinoid receptor-1 (CB1) antagonist, and fully reversed by cotreatment with both agents. We further show that MAGL is part of a gene signature correlated with epithelial-to-mesenchymal transition and the stem-like properties of cancer cells, supporting a role for this enzyme in protumorigenic metabolism that, for prostate cancer, involves the dual control of endocannabinoid and fatty acid pathways.
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Affiliation(s)
- Daniel K Nomura
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
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62
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Alternative targets within the endocannabinoid system for future treatment of gastrointestinal diseases. CANADIAN JOURNAL OF GASTROENTEROLOGY = JOURNAL CANADIEN DE GASTROENTEROLOGIE 2011; 25:377-83. [PMID: 21876860 DOI: 10.1155/2011/953975] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Many beneficial effects of herbal and synthetic cannabinoids on gut motility and inflammation have been demonstrated, suggesting a vast potential for these compounds in the treatment of gastrointestinal disorders. These effects are based on the so-called 'endocannabinoid system' (ECS), a cooperating network of molecules that regulate the metabolism of the body's own and of exogenously administered cannabinoids. The ECS in the gastrointestinal tract quickly responds to homeostatic disturbances by de novo synthesis of its components to maintain homeostasis, thereby offering many potential targets for pharmacological intervention. Of major therapeutic interest are nonpsychoactive cannabinoids or compounds that do not directly target cannabinoid receptors but still possess cannabinoid-like properties. Drugs that inhibit endocannabinoid degradation and raise the level of endocannabinoids are becoming increasingly promising alternative therapeutic tools to manipulate the ECS.
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63
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Fatty acid amide hydrolase expression during retinal postnatal development in rats. Neuroscience 2011; 195:145-65. [PMID: 21867744 DOI: 10.1016/j.neuroscience.2011.08.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2011] [Revised: 07/12/2011] [Accepted: 08/03/2011] [Indexed: 01/01/2023]
Abstract
The endocannabinoid (eCB) system is thought to participate in developmental processes in the CNS. The rodent retina represents a valuable model to study CNS development because it contains well-identified cell types with established developmental timelines. The distribution of cannabinoid receptor type 1 (CB1R) was recently revealed in the developing retina; however, the expression patterns of other elements of this system remain unknown. In this study, we investigated the expression pattern of the degradative enzyme fatty acid amide hydrolase (FAAH), a key regulator of the eCB system, in the rat retina during postnatal development. To identify the cells expressing the enzyme, co-stainings were carried out for FAAH and retinal cell type markers. FAAH was expressed at postnatal day (P) 1 in ganglion and cholinergic amacrine cells. In the course of development, it appeared in cones, horizontal, and bipolar cells. For most cell types (horizontal, cholinergic amacrine cells, and cone bipolar cells), FAAH was transiently expressed, suggesting an important redistribution of the enzyme during postnatal development and thus a potential role of the eCB system in developmental processes. Our results also indicated that, in the adult retina, FAAH is expressed in cones, rod bipolar cells, and some retinal ganglion cells. The presence of FAAH in adult animals supports the hypothesis that the eCB system is involved in retinal functions. Overall these results indicate that, as shown in other structures of the brain, the eCB system could play an instrumental role in the development and function of the retina.
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64
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Serrano A, Parsons LH. Endocannabinoid influence in drug reinforcement, dependence and addiction-related behaviors. Pharmacol Ther 2011; 132:215-41. [PMID: 21798285 DOI: 10.1016/j.pharmthera.2011.06.005] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 06/17/2011] [Indexed: 12/12/2022]
Abstract
The endogenous cannabinoid system is an important regulatory system involved in physiological homeostasis. Endocannabinoid signaling is known to modulate neural development, immune function, metabolism, synaptic plasticity and emotional state. Accumulating evidence also implicates brain endocannabinoid signaling in the etiology of drug addiction which is characterized by compulsive drug seeking, loss of control in limiting drug intake, emergence of a negative emotional state in the absence of drug use and a persistent vulnerability toward relapse to drug use during protracted abstinence. In this review we discuss the effects of drug intake on brain endocannabinoid signaling, evidence implicating the endocannabinoid system in the motivation for drug consumption, and drug-induced alterations in endocannabinoid function that may contribute to various aspects of addiction including dysregulated synaptic plasticity, increased stress responsivity, negative affective states, drug craving and relapse to drug taking. Current knowledge of genetic variants in endocannabinoid signaling associated with addiction is also discussed.
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Affiliation(s)
- Antonia Serrano
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA 92037, USA
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65
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Duclos RI, Johnston M, Vadivel SK, Makriyannis A, Glaser ST, Gatley SJ. A methodology for radiolabeling of the endocannabinoid 2-arachidonoylglycerol (2-AG). J Org Chem 2011; 76:2049-55. [PMID: 21370840 PMCID: PMC3064716 DOI: 10.1021/jo102277q] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The metabolic intermediate and endocannabinoid signaling lipid 2-arachidonoylglycerol (2-AG) has not been readily labeled, primarily because of its instability toward rearrangement. We now detail a synthetic method that easily gives tritiated 2-AG from [5,6,8,9,11,12,14,15-(3)H(N)]arachidonic acid in two steps. We utilized a short chain 1,3-diacylglycerol and proceeded through the "structured lipid" [5'',6'',8'',9'',11'',12'',14'',15''-(3)H(N)]2-arachidonoyl-1,3-dibutyrylglycerol, a triacylglycerol that was conveniently deprotected in ethanol with acrylic beads containing Candida antarctica lipase B to give [5'',6'',8'',9'',11'',12'',14'',15''-(3)H(N)]2-arachidonoylglycerol ([(3)H]2-AG). The flash chromatographic separation necessary to isolate the labeled 2-acylglycerol [(3)H]2-AG resulted in only 4% of the rearrangement byproducts that have been a particular problem with previous methodologies. This reliable "kit" method to prepare the radiolabeled endocannabinoid as needed gave tritiated 2-arachidonoylglycerol [(3)H]2-AG with a specific activity of 200 Ci/mmol for enzyme assays, metabolic studies, and tissue imaging. It has been run on unlabeled materials on over 10 mg scales and should be generally applicable to other 2-acylglycerols.
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Affiliation(s)
- Richard I Duclos
- Department of Pharmaceutical Sciences, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, USA.
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66
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Vadivel SK, Whitten KM, Makriyannis A. Chemoenzymatic Synthesis of 2-Arachidonoylglycerol, An Endogenous Ligand for Cannabinoid Receptors. Tetrahedron Lett 2011; 52:1149-1150. [PMID: 21318079 DOI: 10.1016/j.tetlet.2011.01.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A simple and efficient synthesis of 2-arachidonoyl glycerol, an endogenous agonist for cannabinoid receptors was achieved using Novozym 435, immobilized lipase from Candida Antarctica.
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Affiliation(s)
- Subramanian K Vadivel
- Center for Drug Discovery, 116 Mugar Hall, 360 Huntington Avenue, Northeastern University, Boston, MA 02115
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67
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Ueda N, Tsuboi K, Uyama T, Ohnishi T. Biosynthesis and degradation of the endocannabinoid 2-arachidonoylglycerol. Biofactors 2011; 37:1-7. [PMID: 21328621 DOI: 10.1002/biof.131] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 09/20/2010] [Indexed: 11/11/2022]
Abstract
2-Arachidonoylglycerol (2-AG) is a monoacylglycerol (MAG) molecule containing an esterified arachidonic acid chain at sn-2 position of the glycerol backbone. Together with structurally similar N-arachidonoylethanolamine (anandamide), 2-AG has been extensively studied as an endogenous ligand of cannabinoid receptors (an endocannabinoid) in brain and other mammalian tissues. Accumulating evidence demonstrates that the endocannabinoid system, including the central-type cannabinoid receptor CB1 and 2-AG, is responsible for synaptic retrograde signaling in the central nervous system. As 2-AG is rapidly formed from membrane phospholipids on cellular stimuli and degraded to arachidonic acid and glycerol, the enzymes catalyzing its biosynthesis and degradation are believed to play crucial roles in the regulation of its tissue levels. The major biosynthetic pathway appears to consist of sequential hydrolyses of inositol phospholipids via diacylglycerol (DAG) by β-type phospholipase C and DAG lipase, while MAG lipase is a principal enzyme in the degradation. In this short review, we will briefly outline rapid advances in enzymological research on the biosynthetic and degradative pathways of 2-AG.
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Affiliation(s)
- Natsuo Ueda
- Department of Biochemistry, Kagawa University School of Medicine, 1750-1 Ikenobe, Miki, Kagawa, Japan.
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68
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Björklund E, Norén E, Nilsson J, Fowler CJ. Inhibition of monoacylglycerol lipase by troglitazone, N-arachidonoyl dopamine and the irreversible inhibitor JZL184: comparison of two different assays. Br J Pharmacol 2010; 161:1512-26. [PMID: 20735405 PMCID: PMC3010564 DOI: 10.1111/j.1476-5381.2010.00974.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 06/22/2010] [Accepted: 07/12/2010] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE Drugs used clinically usually have a primary mechanism of action, but additional effects on other biological targets can contribute to their effects. A potentially useful additional target is the endocannabinoid metabolizing enzyme monoacylglycerol lipase (MGL). We have screened a range of drugs for inhibition of MGL and compared the observed potencies using different MGL enzyme assays. EXPERIMENTAL APPROACH MGL activity was screened using recombinant human MGL (cell lysates and purified enzyme) with 4-nitrophenyl acetate (NPA) as substrate. 2-Oleolyglycerol metabolism by rat cerebellar cytosolic MGL and by recombinant MGL was also investigated. KEY RESULTS Among the 96 compounds screened in the NPA assay, troglitazone, CP55,940, N-arachidonoyl dopamine and AM404 inhibited NPA hydrolysis by the lysates with IC(50) values of 1.1, 4.9, 0.78 and 3.1µM, respectively. The potency for troglitazone is in the same range as its primary pharmacological activity, activation of peroxisome proliferator-activated receptor (PPAR) γ. Among PPARγ ligands, the potency order towards human MGL was troglitazone > ciglitazone > rosiglitazone > 15-deoxy-Δ(12,14) -prostaglandin J(2) ≈ CAY 10415 > CAY 10514. In contrast to the time-dependent inhibitor JZL184, the potency of troglitazone was dependent upon the enzyme assay system used. Thus, troglitazone inhibited rat cytosolic 2-oleoylglycerol hydrolysis less potently (IC(50) 41µM) than hydrolysis of NPA by the human MGL lysates. CONCLUSIONS AND IMPLICATIONS 'Hits' in screening programmes for MGL inhibitors should be assessed in different MGL assays. Troglitazone may be a useful lead for the design of novel, dual action MGL inhibitors/PPARγ activators.
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Affiliation(s)
- E Björklund
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
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69
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Scotter EL, Abood ME, Glass M. The endocannabinoid system as a target for the treatment of neurodegenerative disease. Br J Pharmacol 2010; 160:480-98. [PMID: 20590559 DOI: 10.1111/j.1476-5381.2010.00735.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The Cannabis sativa plant has been exploited for medicinal, agricultural and spiritual purposes in diverse cultures over thousands of years. Cannabis has been used recreationally for its psychotropic properties, while effects such as stimulation of appetite, analgesia and anti-emesis have lead to the medicinal application of cannabis. Indeed, reports of medicinal efficacy of cannabis can been traced back as far as 2700 BC, and even at that time reports also suggested a neuroprotective effect of the cultivar. The discovery of the psychoactive component of cannabis resin, Delta(9)-tetrahydrocannabinol (Delta(9)-THC) occurred long before the serendipitous identification of a G-protein coupled receptor at which Delta(9)-THC is active in the brain. The subsequent finding of endogenous cannabinoid compounds, the synthesis of which is directed by neuronal excitability and which in turn served to regulate that excitability, further widened the range of potential drug targets through which the endocannabinoid system can be manipulated. As a result of this, alterations in the endocannabinoid system have been extensively investigated in a range of neurodegenerative disorders. In this review we examine the evidence implicating the endocannabinoid system in the cause, symptomatology or treatment of neurodegenerative disease. We examine data from human patients and compare and contrast this with evidence from animal models of these diseases. On the basis of this evidence we discuss the likely efficacy of endocannabinoid-based therapies in each disease context.
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Affiliation(s)
- Emma L Scotter
- Centre for Brain Research and Department of Pharmacology, University of Auckland, Auckland, New Zealand
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70
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Evagorou A, Anagnostopoulos D, Farmaki E, Siafaka-Kapadai A. Hydrolysis of 2-arachidonoylglycerol in Tetrahymena thermophila. Identification and partial characterization of a Monoacylglycerol Lipase-like enzyme. Eur J Protistol 2010; 46:289-97. [PMID: 20889319 DOI: 10.1016/j.ejop.2010.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 06/01/2010] [Accepted: 06/11/2010] [Indexed: 11/19/2022]
Abstract
Tetrahymena thermophila is a model organism for molecular and cellular biology. Previous studies from our group showed that Tetrahymena contains major components of the endocannabinoid system, such as various endocannabinoids and FAAH. In mammalian cells the endocannabinoid 2-arachidonoylglycerol is inactivated mainly by MAGL. In this study we showed that 2-arachidonoylglycerol and 2-oleoylglycerol are hydrolyzed by the combined actions of MAGL and FAAH. MAGL-like activity was examined in the presence of FAAH specific inhibitors, URB597 or AM374 and showed optimum pH of 8-9, apparent K(M) of 14.1μM and V(max) of 5.8nmol/min×mg. The enzyme was present in membrane bound and cytosolic isoforms; molecular mass was determined at ∼45 and ∼40kDa. MAGL and FAAH could also inactivate endogenous signaling lipids, which might play an important role in Tetrahymena as suggested in mammals. Tetrahymena could be used as a model system for testing drugs targeting enzymes of the endocannabinoid system.
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Affiliation(s)
- Andri Evagorou
- National and Kapodistrian University of Athens, Department of Chemistry (Biochemistry), University of Athens, Panepistimioupolis, 15771 Athens, Greece
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71
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Pope C, Mechoulam R, Parsons L. Endocannabinoid signaling in neurotoxicity and neuroprotection. Neurotoxicology 2010; 31:562-71. [PMID: 19969019 PMCID: PMC2891218 DOI: 10.1016/j.neuro.2009.12.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 12/02/2009] [Indexed: 01/23/2023]
Abstract
The cannabis plant and products produced from it, such as marijuana and hashish, have been used for centuries for their psychoactive properties. The mechanism for how Delta(9)-tetrahydrocannabinol (THC), the active constituent of cannabis, elicits these neurological effects remained elusive until relatively recently, when specific G-protein coupled receptors were discovered that appeared to mediate cellular actions of THC. Shortly after discovery of these specific receptors, endogenous ligands (endocannabinoids) were identified. Since that time, an extensive number of papers have been published on the endocannabinoid signaling system, a widespread neuromodulatory mechanism that influences neurotransmission throughout the nervous system. This paper summarizes presentations given at the 12th International Neurotoxicology Association meeting that described the potential role of endocannabinoids in the expression of neurotoxicity. Dr. Raphael Mechoulam first gave an overview of the discovery of exogenous and endogenous cannabinoids and their potential for neuroprotection in a variety of conditions. Dr. Larry Parsons then described studies suggesting that endocannabinoid signaling may play a selective role in drug reinforcement. Dr. Carey Pope presented information on the role that endocannabinoid signaling may have in the expression of cholinergic toxicity following anticholinesterase exposures. Together, these presentations highlighted the diverse types of neurological insults that may be modulated by endocannabinoids and drugs/toxicants which might influence endocannabinoid signaling pathways.
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Affiliation(s)
- C Pope
- Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, USA.
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72
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Retraction. J Labelled Comp Radiopharm 2010. [DOI: 10.1002/jlcr.1781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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73
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Deng H. Recent advances in the discovery and evaluation of fatty acid amide hydrolase inhibitors. Expert Opin Drug Discov 2010; 5:961-93. [PMID: 22823990 DOI: 10.1517/17460441.2010.513378] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Cannabis has been used for both medicinal and recreational purposes since ancient times. Although cannabinoid-based medicines hold great promise in several challenging therapeutic areas such as pain management and mode control, their development has been hampered by psychoactive and other CNS-related side effects. The identification of fatty acid amide hydrolase (FAAH), a key enzyme responsible for the degradation of endocannabinoids, has brought in tremendous opportunities in that inhibition of FAAH leads to local elevation of endocannabinoids under certain stimuli, thus, avoiding the side effects from global activation of cannabinoid receptors by exogenous cannabimimetic compounds. The search for selective FAAH inhibitors has thus become a strong focus in current drug discovery. AREAS COVERED IN THIS REVIEW This review summarizes our current understanding of FAAH including its structure, catalytic mechanism and biological functions with emphases on its role in the regulation of endocannabinoids and other signaling lipids. The review then highlights the most recent discovery and biological activities of different classes of FAAH inhibitors. Last, the review discusses challenges and potential drawbacks in the development of FAAH inhibitor-based therapy. WHAT THE READER WILL GAIN Readers will have an overview of FAAH and obtain a rationale on FAAH as an attractive therapeutic target for the development of medicines for treating pain, inflammation, anxiety and other diseases. More importantly, readers will gain knowledge on various newly established FAAH inhibitor scaffolds and their development potentials, and such information will hopefully stimulate ideas for the designing of new inhibitors with superior activity profiles. The discussions on the potential challenges in developing FAAH inhibitors will impose more caution in the decision-making process, thus, lowering the possibility of late stage failure. TAKE HOME MESSAGE FAAH is an attractive target for modulating the endocannabinoid system, thus, treating many disease conditions including pain and mode control without the CNS side effects associated with cannabis usage. In recent years, tremendous effort has been focused in the FAAH inhibitor research field, and consequently many novel chemical templates have been discovered. FAAH hydrolyzes several important signaling lipids, but the long-term effects of FAAH inhibition in humans remain to be seen. While it is challenging to identify the right molecule with the right level of intervention of the FAAH function for treating a disease condition, it is possible to avoid mechanism-related undesired effects. With the entry of several compounds into clinical trials, FAAH inhibitor-based medicines are on the horizon.
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Affiliation(s)
- Hongfeng Deng
- GlaxoSmithKline, Platform Technology & Science/Molecular Discovery Research, ELT-Boston, 830 Winter Street, Waltham, MA 02451, USA
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74
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Thors L, Bergh A, Persson E, Hammarsten P, Stattin P, Egevad L, Granfors T, Fowler CJ. Fatty acid amide hydrolase in prostate cancer: association with disease severity and outcome, CB1 receptor expression and regulation by IL-4. PLoS One 2010; 5:e12275. [PMID: 20808855 PMCID: PMC2924377 DOI: 10.1371/journal.pone.0012275] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 07/27/2010] [Indexed: 01/02/2023] Open
Abstract
Background Recent data have indicated that there may be a dysregulation of endocannabinoid metabolism in cancer. Here we have investigated the expression of the endocannabinoid metabolising enzyme fatty acid amide hydrolase (FAAH) in a well characterised tissue microarray from patients diagnosed with prostate cancer at transurethral resection for voiding problems. Methodology/Principal Findings FAAH immunoreactivity (FAAH-IR) was assessed in formalin-fixed paraffin-embedded non-malignant and tumour cores from 412 patients with prostate cancer. CB1 receptor immunoreactivity (CB1IR) scores were available for this dataset. FAAH-IR was seen in epithelial cells and blood vessel walls but not in the stroma. Tumour epithelial FAAH-IR was positively correlated with the disease severity at diagnosis (Gleason score, tumour stage, % of the specimen that contained tumour) for cases with mid-range CB1IR scores, but not for those with high CB1IR scores. For the 281 cases who only received palliative therapy at the end stages of the disease, a high tumour epithelial FAAH-IR was associated with a poor disease-specific survival. Multivariate Cox proportional-hazards regression analyses indicated that FAAH-IR gave additional prognostic information to that provided by CB1IR when a midrange, but not a high CB1IR cutoff value was used. Interleukin-4 (IL-4) receptor IR was found on tumour epithelial cells and incubation of prostate cancer PC-3 and R3327 AT1 cells with IL-4 increased their FAAH activity. Conclusions/Significance Tumour epithelial FAAH-IR is associated with prostate cancer severity and outcome at mid-range, but not high, CB1IR scores. The correlation with CB1IR in the tumour tissue may be related to a common local dysregulation by a component of the tumour microenvironment.
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Affiliation(s)
- Lina Thors
- Pharmacology Unit, Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Anders Bergh
- Pathology Unit, Department of Medical Biosciences, Umeå University, Umeå, Sweden
| | - Emma Persson
- Departments of Oncology and Radiation Sciences, Umeå University, Umeå, Sweden
| | - Peter Hammarsten
- Pathology Unit, Department of Medical Biosciences, Umeå University, Umeå, Sweden
| | - Pär Stattin
- Urology and Andrology Unit, Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden
| | - Lars Egevad
- Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden
| | | | - Christopher J. Fowler
- Pharmacology Unit, Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
- * E-mail:
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75
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Marrs WR, Blankman JL, Horne EA, Thomazeau A, Lin YH, Coy J, Bodor AL, Muccioli GG, Hu SSJ, Woodruff G, Fung S, Lafourcade M, Alexander JP, Long JZ, Li W, Xu C, Möller T, Mackie K, Manzoni OJ, Cravatt BF, Stella N. The serine hydrolase ABHD6 controls the accumulation and efficacy of 2-AG at cannabinoid receptors. Nat Neurosci 2010; 13:951-7. [PMID: 20657592 DOI: 10.1038/nn.2601] [Citation(s) in RCA: 330] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 06/23/2010] [Indexed: 11/09/2022]
Abstract
The endocannabinoid 2-arachidonoylglycerol (2-AG) regulates neurotransmission and neuroinflammation by activating CB1 cannabinoid receptors on neurons and CB2 cannabinoid receptors on microglia. Enzymes that hydrolyze 2-AG, such as monoacylglycerol lipase, regulate the accumulation and efficacy of 2-AG at cannabinoid receptors. We found that the recently described serine hydrolase alpha-beta-hydrolase domain 6 (ABHD6) also controls the accumulation and efficacy of 2-AG at cannabinoid receptors. In cells from the BV-2 microglia cell line, ABHD6 knockdown reduced hydrolysis of 2-AG and increased the efficacy with which 2-AG can stimulate CB2-mediated cell migration. ABHD6 was expressed by neurons in primary culture and its inhibition led to activity-dependent accumulation of 2-AG. In adult mouse cortex, ABHD6 was located postsynaptically and its selective inhibition allowed the induction of CB1-dependent long-term depression by otherwise subthreshold stimulation. Our results indicate that ABHD6 is a rate-limiting step of 2-AG signaling and is therefore a bona fide member of the endocannabinoid signaling system.
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Affiliation(s)
- William R Marrs
- Neurobiology and Behavior Graduate Program, University of Washington, Seattle, Washington, USA
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76
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Buczynski MW, Parsons LH. Quantification of brain endocannabinoid levels: methods, interpretations and pitfalls. Br J Pharmacol 2010; 160:423-42. [PMID: 20590555 PMCID: PMC2931546 DOI: 10.1111/j.1476-5381.2010.00787.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 03/12/2010] [Accepted: 03/20/2010] [Indexed: 02/03/2023] Open
Abstract
Endocannabinoids play an important role in a diverse range of neurophysiological processes including neural development, neuroimmune function, synaptic plasticity, pain, reward and affective state. This breadth of influence and evidence for altered endocannabinoid signalling in a variety of neuropathologies has fuelled interest in the accurate quantification of these lipids in brain tissue. Established methods for endocannabinoid quantification primarily employ solvent-based lipid extraction with further sample purification by solid phase extraction. In recent years in vivo microdialysis methods have also been developed for endocannabinoid sampling from the brain interstitial space. However, considerable variability in estimates of endocannabinoid content has led to debate regarding the physiological range of concentrations present in various brain regions. This paper provides a critical review of factors that influence the quantification of brain endocannabinoid content as determined by lipid extraction from bulk tissue and by in vivo microdialysis. A variety of methodological issues are discussed including analytical approaches, endocannabinoid extraction and purification, post-mortem changes in brain endocannabinoid content, cellular reactions to microdialysis probe implantation and caveats related to lipid sampling from the extracellular space. The application of these methods for estimating brain endocannabinoid content and the effects of endocannabinoid clearance inhibition are discussed. The benefits, limitations and pitfalls associated with each approach are emphasized, with an eye toward the appropriate interpretation of data gathered by each method.
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Affiliation(s)
- Matthew W Buczynski
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
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77
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Käsnänen H, Myllymäki MJ, Minkkilä A, Kataja AO, Saario SM, Nevalainen T, Koskinen AMP, Poso A. 3-Heterocycle-phenyl N-alkylcarbamates as FAAH inhibitors: design, synthesis and 3D-QSAR studies. ChemMedChem 2010; 5:213-31. [PMID: 20024981 DOI: 10.1002/cmdc.200900390] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Carbamates are a well-established class of fatty acid amide hydrolase (FAAH) inhibitors. Here we describe the synthesis of meta-substituted phenolic N-alkyl/aryl carbamates and their in vitro FAAH inhibitory activities. The most potent compound, 3-(oxazol-2yl)phenyl cyclohexylcarbamate (2 a), inhibited FAAH with a sub-nanomolar IC(50) value (IC(50)=0.74 nM). Additionally, we developed and validated three-dimensional quantitative structure-activity relationships (QSAR) models of FAAH inhibition combining the newly disclosed carbamates with our previously published inhibitors to give a total set of 99 compounds. Prior to 3D-QSAR modeling, the degree of correlation between FAAH inhibition and in silico reactivity was also established. Both 3D-QSAR methods used, CoMSIA and GRID/GOLPE, produced statistically significant models with coefficient of correlation for external prediction (R(2) (PRED)) values of 0.732 and 0.760, respectively. These models could be of high value in further FAAH inhibitor design.
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Affiliation(s)
- Heikki Käsnänen
- Department of Pharmaceutical Chemistry, University of Kuopio, P.O.Box 1627, 70211 Kuopio, Finland
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78
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Naidu PS, Kinsey SG, Guo TL, Cravatt BF, Lichtman AH. Regulation of inflammatory pain by inhibition of fatty acid amide hydrolase. J Pharmacol Exp Ther 2010; 334:182-90. [PMID: 20375198 DOI: 10.1124/jpet.109.164806] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Although cannabinoids are efficacious in laboratory animal models of inflammatory pain, their established cannabimimetic actions diminish enthusiasm for their therapeutic development. Conversely, fatty acid amide hydrolase (FAAH), the chief catabolic enzyme regulating the endogenous cannabinoid N-arachidonoylethanolamine (anandamide), has emerged as an attractive target for treating pain and other conditions. Here, we tested WIN 55212-2 [(R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de)-1,4-benzoxazin-6-yl]-1-napthalenylmethanone], a cannabinoid receptor agonist, and genetic deletion or pharmacological inhibition of FAAH in the lipopolysaccharide (LPS) mouse model of inflammatory pain. WIN 55212-2 significantly reduced edema and hot-plate hyperalgesia caused by LPS infusion into the hind paws, although the mice also displayed analgesia and other central nervous system effects. FAAH(-/-) mice exhibited reduced paw edema and hyperalgesia in this model without apparent cannabimimetic effects. Transgenic mice expressing FAAH exclusively on neurons continued to display the antiedematous, but not the antihyperalgesic, phenotype. The CB(2) cannabinoid receptor (CB(2)) antagonist SR144528 [N-[(1S)-endo-1,3,3-trimethyl bicyclo [2.2.1] heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide] blocked this non-neuronal, anti-inflammatory phenotype, and the CB(1) cannabinoid receptor (CB(1)) antagonist rimonabant [SR141716, N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide] blocked the antihyperalgesic phenotype. The FAAH inhibitor URB597 [cyclohexylcarbamic acid 3'-carbamoylbiphenyl-3-yl ester] attenuated the development of LPS-induced paw edema and reversed LPS-induced hyperalgesia through the respective CB(2) and CB(1) mechanisms of action. However, the transient receptor potential vanilloid type 1 antagonist capsazepine did not affect either the antihyperalgesic or antiedematous effects of URB597. Finally, URB597 attenuated levels of the proinflammatory cytokines interleukin-1beta and tumor necrosis factor alpha in LPS-treated paws. These findings demonstrate that simultaneous elevations in non-neuronal and neuronal endocannabinoid signaling are possible through inhibition of a single enzymatic target, thereby offering a potentially powerful strategy for treating chronic inflammatory pain syndromes that operate at multiple levels of anatomical integration.
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Affiliation(s)
- Pattipati S Naidu
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298, USA
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79
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Levels of endocannabinoids and palmitoylethanolamide and their pharmacological manipulation in chronic granulomatous inflammation in rats. Pharmacol Res 2010; 61:321-8. [DOI: 10.1016/j.phrs.2009.11.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 11/10/2009] [Accepted: 11/11/2009] [Indexed: 11/17/2022]
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80
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Placzek EA, Cooper BR, Placzek AT, Chester JA, Davisson VJ, Barker EL. Lipidomic metabolism analysis of the endogenous cannabinoid anandamide (N-arachidonylethanolamide). J Pharm Biomed Anal 2010; 53:567-75. [PMID: 20417049 DOI: 10.1016/j.jpba.2010.03.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 03/19/2010] [Accepted: 03/26/2010] [Indexed: 01/21/2023]
Abstract
Elucidation of pathways involved with lipid metabolism has been limited by analytical challenges associated with detection and structure identification. A discovery-based mass spectrometry lipidomic approach has been applied to identify metabolites of the endogenous cannabinoid anandamide (N-arachidonylethanolamide). Previously, a model system was established to show that anandamide can be recycled by cells to form new endocannabinoids suggesting recycling of the arachidonate carbon chain. We hypothesized that distinct cellular pathways exist to direct the anandamide-derived arachidonate chain into a specific set of metabolites, different from the metabolite pool that is comprised of non-anandamide-derived arachidonic acid. Using stable isotope encoding and liquid chromatography-mass spectrometry, we identified a distinct pool of lipid metabolites derived from exogenous anandamide or arachidonic acid in RBL-2H3 cells. We discovered that arachidonic acid-derived metabolites were primarily comprised of the eicosanoid lipid class, whereas anandamide-derived arachidonic acid, in addition to eicosanoids, was metabolized into diradylglycerols, fatty acid amides, sterols, and glycerophospholipids. From the list of anandamide metabolites of particular interest was 1-O-arachidonyl-sn-glycero-3-phosphocholine. Furthermore, we determined that while 1-O-arachidonyl-sn-glycero-3-phosphocholine may be a metabolite of anandamide, the sn-2 compound was more abundant in mouse brain tissue. Overall, our results provide a novel approach to study the metabolic fate of endocannabinoids and fatty acid-derived signaling molecules.
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Affiliation(s)
- Ekaterina A Placzek
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47904, United States
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81
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Taylor AH, Amoako AA, Bambang K, Karasu T, Gebeh A, Lam PMW, Marzcylo TH, Konje JC. Endocannabinoids and pregnancy. Clin Chim Acta 2010; 411:921-30. [PMID: 20302856 DOI: 10.1016/j.cca.2010.03.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 03/09/2010] [Accepted: 03/09/2010] [Indexed: 12/12/2022]
Abstract
Acylethanolamides such as anandamide (AEA), and monoacylglycerols like 2-arachidonoylglycerol are endocannabinoids that bind to cannabinoid, vanilloid and peroxisome proliferator-activated receptors. These compounds, their various receptors, the purported membrane transporter(s), and related enzymes that synthesize and degrade them are collectively referred to as the "endocannabinoid system (ECS)". Poorly defined cellular and molecular mechanisms control the biological actions of the ECS. Over the last decade evidence has been emerging to suggest that the ECS plays a significant role in various aspects of human reproduction. In this review, we summarize our current understanding of this role especially the involvement of AEA and related ECS elements in regulating oogenesis, embryo oviductal transport, blastocyst implantation, placental development and pregnancy outcomes, and sperm survival, motility, capacitation and acrosome reaction. Additionally, the possibility that plasma and tissue AEA and other cannabinoids may represent reliable diagnostic markers of natural and assisted reproduction and pregnancy outcomes in women will be discussed.
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Affiliation(s)
- Anthony H Taylor
- Reproductive Sciences Section, University of Leicester, Leicester, United Kingdom
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82
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Ueda N, Tsuboi K, Uyama T. N-acylethanolamine metabolism with special reference to N-acylethanolamine-hydrolyzing acid amidase (NAAA). Prog Lipid Res 2010; 49:299-315. [PMID: 20152858 DOI: 10.1016/j.plipres.2010.02.003] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
N-acylethanolamines (NAEs) constitute a class of bioactive lipid molecules present in animal and plant tissues. Among the NAEs, N-arachidonoylethanolamine (anandamide), N-palmitoylethanolamine, and N-oleoylethanolamine attract much attention due to cannabimimetic activity as an endocannabinoid, anti-inflammatory and analgesic activities, and anorexic activity, respectively. In mammalian tissues, NAEs are formed from glycerophospholipids through the phosphodiesterase-transacylation pathway consisting of Ca(2+)-dependent N-acyltransferase and N-acylphosphatidylethanolamine-hydrolyzing phospholipase D. Recent studies revealed the presence of alternative pathways and enzymes responsible for the NAE formation. As for the degradation of NAEs, fatty acid amide hydrolase (FAAH), which hydrolyzes NAEs to fatty acids and ethanolamine, plays a central role. However, a lysosomal enzyme referred to as NAE-hydrolyzing acid amidase (NAAA) also catalyzes the same reaction and may be a new target for the development of therapeutic drugs. In this article we discuss recent progress in the studies on the enzymes involved in the biosynthesis and degradation of NAEs with special reference to NAAA.
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Affiliation(s)
- Natsuo Ueda
- Department of Biochemistry, Kagawa University School of Medicine, 1750-1 Ikenobe, Miki, Kagawa, Japan
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83
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Zhang MY, Gao Y, Btesh J, Kagan N, Kerns E, Samad TA, Chanda PK. Simultaneous determination of 2-arachidonoylglycerol, 1-arachidonoylglycerol and arachidonic acid in mouse brain tissue using liquid chromatography/tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2010; 45:167-177. [PMID: 19950120 DOI: 10.1002/jms.1701] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Endocannabinoids (ECs), such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG), modulate a number of physiological processes, including pain, appetite and emotional state. Levels of ECs are tightly controlled by enzymatic biosynthesis and degradation in vivo. However, there is limited knowledge about the enzymes that terminate signaling of the major brain EC, 2-AG. Identification and quantification of 2-AG, 1-AG and arachidonic acid (AA) is important for studying the enzymatic hydrolysis of 2-AG. We have developed a sensitive and specific quantification method for simultaneous determination of 2-AG, 1-AG and AA from mouse brain and adipose tissues by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using a simple brain sample preparation method. The separations were carried out based on reversed phase chromatography. Optimization of electrospray ionization conditions established the limits of detection (S/N = 3) at 50, 25 and 65 fmol for 2-AG, 1-AG and AA, respectively. The methods were selective, precise (%R.S.D. < 10%) and sensitive over a range of 0.02-20, 0.01-10 and 0.05-50 ng/mg tissue for 2-AG, 1-AG and AA, respectively. The quantification method was validated with consideration of the matrix effects and the mass spectrometry (MS) responses of the analytes and the deuterium labeled internal standard (IS). The developed methods were applied to study the hydrolysis of 2-AG from mouse brain extracts containing membrane bound monoacylglycerol lipase (MAGL), and to measure the basal levels of 2-AG, 1-AG and AA in mouse brain and adipose tissues.
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Affiliation(s)
- Mei-Yi Zhang
- Chemical Sciences, Wyeth Research, CN 8000, Princeton, NJ 08543, USA.
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84
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Bertrand T, Augé F, Houtmann J, Rak A, Vallée F, Mikol V, Berne PF, Michot N, Cheuret D, Hoornaert C, Mathieu M. Structural basis for human monoglyceride lipase inhibition. J Mol Biol 2009; 396:663-73. [PMID: 19962385 DOI: 10.1016/j.jmb.2009.11.060] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 11/24/2009] [Accepted: 11/24/2009] [Indexed: 11/16/2022]
Abstract
Monoglyceride lipase (MGL) is a serine hydrolase that hydrolyses 2-arachidonoylglycerol (2-AG) into arachidonic acid and glycerol. 2-AG is an endogenous ligand of cannabinoid receptors, involved in various physiological processes in the brain. We present here the first crystal structure of human MGL in its apo form and in complex with the covalent inhibitor SAR629. MGL shares the classic fold of the alpha/beta hydrolase family but depicts an unusually large hydrophobic occluded tunnel with a highly flexible lid at its entry and the catalytic triad buried at its end. Structures reveal the configuration of the catalytic triad and the shape and nature of the binding site of 2-AG. The bound structure of SAR629 highlights the key interactions for productive binding with MGL. The shape of the tunnel suggests a high druggability of the protein and provides an attractive template for drug discovery.
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Affiliation(s)
- T Bertrand
- Department of Structural Biology, Sanofi-Aventis, 13 Quai Jules Guesde, 94403 Vitry-sur-Seine cedex, France.
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85
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Bowman AL, Makriyannis A. Refined homology model of monoacylglycerol lipase: toward a selective inhibitor. J Comput Aided Mol Des 2009; 23:799-806. [PMID: 19543978 PMCID: PMC3308346 DOI: 10.1007/s10822-009-9289-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 05/29/2009] [Indexed: 11/28/2022]
Abstract
Monoacylglycerol lipase (MGL) is primarily responsible for the hydrolysis of 2-arachidonoylglycerol (2-AG), an endocannabinoid with full agonist activity at both cannabinoid receptors. Increased tissue 2-AG levels consequent to MGL inhibition are considered therapeutic against pain, inflammation, and neurodegenerative disorders. However, the lack of MGL structural information has hindered the development of MGL-selective inhibitors. Here, we detail a fully refined homology model of MGL which preferentially identifies MGL inhibitors over druglike noninhibitors. We include for the first time insight into the active-site geometry and potential hydrogen-bonding interactions along with molecular dynamics simulations describing the opening and closing of the MGL helical-domain lid. Docked poses of both the natural substrate and known inhibitors are detailed. A comparison of the MGL active-site to that of the other principal endocannabinoid metabolizing enzyme, fatty acid amide hydrolase, demonstrates key differences which provide crucial insight toward the design of selective MGL inhibitors as potential drugs.
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Affiliation(s)
- Anna L Bowman
- Center for Drug Discovery, Northeastern University, Boston, MA 02115, USA.
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86
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Guindon J, Hohmann AG. The endocannabinoid system and pain. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2009; 8:403-21. [PMID: 19839937 DOI: 10.2174/187152709789824660] [Citation(s) in RCA: 318] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Accepted: 06/24/2009] [Indexed: 12/29/2022]
Abstract
The therapeutic potential of cannabinoids has been the topic of extensive investigation following the discovery of cannabinoid receptors and their endogenous ligands. Cannabinoid receptors and their endogenous ligands are present at supraspinal, spinal and peripheral levels. Cannabinoids suppress behavioral responses to noxious stimulation and suppress nociceptive processing through activation of cannabinoid CB(1) and CB(2) receptor subtypes. Endocannabinoids, the brain's own cannabis-like substances, share the same molecular target as Delta(9)-tetrahydrocannabinol, the main psychoactive component in cannabis. Endocannabinoids serve as synaptic circuit breakers and regulate multiple physiological and pathological conditions, e.g. regulation of food intake, immunomodulation, inflammation, analgesia, cancer, addictive behavior, epilepsy and others. This review will focus on uncovering the roles of anandamide and 2-arachidonoylglycerol, the two best characterized endocannabinoids identified to date, in controlling nociceptive responding. The roles of anandamide and 2-arachidonoylglycerol, released under physiological conditions, in modulating nociceptive responding at different levels of the neuraxis will be emphasized in this review. Effects of modulation of endocannabinoid levels through inhibition of endocannabinoid hydrolysis and uptake is also compared with effects of exogenous administration of synthetic endocannabinoids in acute, inflammatory and neuropathic pain models. Finally, the therapeutic potential of the endocannabinoid signaling system is discussed in the context of identifying novel pharmacotherapies for the treatment of pain.
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Affiliation(s)
- Josée Guindon
- Neuroscience and Behavior Program, Department of Psychology, University of Georgia, Athens, GA 30602-3013, USA
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87
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Wyffels L, Muccioli GG, De Bruyne S, Moerman L, Sambre J, Lambert DM, De Vos F. Synthesis, in vitro and in vivo evaluation, and radiolabeling of aryl anandamide analogues as candidate radioligands for in vivo imaging of fatty acid amide hydrolase in the brain. J Med Chem 2009; 52:4613-22. [PMID: 19719235 DOI: 10.1021/jm900324e] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Fatty acid amide hydrolyase (FAAH) is one of the main enzymes responsible for terminating the signaling of endocannabinoids in the brain. Imaging FAAH in vivo using PET or SPECT is important to deeper understanding of its role in neuropsychiatric disorders. However, at present, no radioligand is available for mapping the enzyme in vivo. Here, we synthesized 18 aryl analogues of anandamide, FAAH's endogenous substrate, and in vitro evaluated their potential as metabolic trapping tracers. Interaction studies with recombinant FAAH revealed good to very good interaction of the methoxy substituted aryl anandamide analogues 17, 18, 19, and 20 with FAAH and they were identified as competing substrates. Compounds 17 and 18 did not display significant binding to CB1 and CB2 cannabinoid receptors and stand out as potential candidate metabolic trapping tracers. They were successfully labeled with 11C in good yields and high radiochemical purity and displayed brain uptake in C57BL/6J mice. Radioligands [11C]-17 and [11C]-18 merit further investigation in vivo.
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Affiliation(s)
- Leonie Wyffels
- Department of Radiopharmacy, Ghent University, Harelbekestraat 72, B-9000 Ghent, Belgium
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88
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Kubajewska I, Constantinescu CS. Cannabinoids and experimental models of multiple sclerosis. Immunobiology 2009; 215:647-57. [PMID: 19765854 DOI: 10.1016/j.imbio.2009.08.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 08/12/2009] [Accepted: 08/14/2009] [Indexed: 01/07/2023]
Abstract
The inflammatory response is a hallmark in the development of autoimmune-mediated neurodegenerative diseases of the central nervous system (CNS). Research on these pathological phenomena is being extensively undertaken and experimental autoimmune encephalomyelitis (EAE) serves as a valuable animal model. Studies from this model have generated interesting insights into biological effects of cannabinoids and may, at least to a certain extent, reflect the cannabinoid-mediated protective mechanisms also in human diseases with similar characteristics, such as multiple sclerosis (MS). Cannabinoids are involved in regulation of the immune system. These effects comprise modulation of inflammatory reaction through components of the innate and adaptive immune responses. Cannabinoids also confer neuroprotection and assist neuroregeneration, thus maintaining a balance within the delicate CNS microenvironment and restoring function following pathological condition, commonly driven by neuroinflammation. Continued studies of cannabinoid actions in EAE pathogenesis should be beneficial for the better understanding of the mechanisms governing such a vast array of physiological effects and in development of new therapeutic strategies for the treatment of human neuroinflammatory and neurodegenerative diseases.
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Affiliation(s)
- Ilona Kubajewska
- Division of Clinical Neurology, University of Nottingham, Queen's Medical Centre, Nottingham NG72UH, UK
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89
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Effect of nitric oxide donors on membrane tritium accumulation of endocannabinoids and related endogenous lipids. Eur J Pharmacol 2009; 621:10-8. [PMID: 19715690 DOI: 10.1016/j.ejphar.2009.08.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 08/13/2009] [Accepted: 08/20/2009] [Indexed: 11/21/2022]
Abstract
The endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) are metabolised by cells by hydrolysis to arachidonic acid followed by esterification into phospholipids. Here, we report that nitric oxide (NO) donors significantly increase the amount of tritium accumulated in the cell membranes of RBL2H3 rat basophilic cells, 3T3-L1 mouse fibroblast cells and b.End5 mouse brain endothelioma cells following incubation of the intact cells with AEA labelled in the arachidonate part of the molecule. Similar results were seen with 2-AG and with arachidonic acid, whilst the NO donors reduced the accumulation of tritium after incubation of RBL2H3 cells with AEA labelled in the ethanolamine part of the molecule. Pretreatment of intact cells with NO donors did not increase the activity of the enzyme mainly responsible for metabolism of AEA, fatty acid amide hydrolase (FAAH). Furthermore, inhibition of FAAH completely blocked the effect produced by NO donors in cells with a large FAAH component, suggesting that for AEA, the effects were downstream of the enzyme. These data raise the possibility that the cellular processing of endocannabinoids following its uptake can be regulated by nitric oxide.
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90
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Ueda N, Tsuboi K, Lambert DM. A second N-acylethanolamine hydrolase in mammalian tissues. Neuropharmacology 2009; 48:1079-85. [PMID: 15910884 DOI: 10.1016/j.neuropharm.2004.12.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 11/30/2004] [Accepted: 12/21/2004] [Indexed: 11/24/2022]
Abstract
It is widely accepted that fatty acid amide hydrolase (FAAH) plays a central role in the hydrolysis of anandamide. However, we found a second N-acylethanolamine hydrolase in animal tissues which hydrolyzed anandamide at acidic pH. This "acid amidase" was first detected with the particulate fraction of human megakaryoblastic CMK cells, and was solubilized by freezing and thawing without detergent. The enzyme was distinguishable from FAAH in terms of (1) the optimal activity at pH 5, (2) stimulation by dithiothreitol, (3) low sensitivity to two FAAH inhibitors (methyl arachidonyl fluorophosphonate and phenylmethylsulfonyl fluoride), and (4) high content in lung, spleen and macrophages of rat. The acid amidase purified from rat lung was the most active with N-palmitoylethanolamine among various long-chain N-acylethanolamines. To develop specific inhibitors for this enzyme, we screened various analogues of N-palmitoylethanolamine. Among the tested compounds, N-cyclohexanecarbonylpentadecylamine was the most potent inhibitor which does-dependently inhibited the enzyme with an IC(50) value of 4.5 microM without inhibiting FAAH at concentrations up to 100 microM. The inhibitor was a useful tool to distinguish the acid amidase from FAAH with rat basophilic leukemia (RBL-1) cells that express both the enzymes.
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Affiliation(s)
- Natsuo Ueda
- Department of Biochemistry, Kagawa University School of Medicine, 1750-1 Ikenobe, Miki, Kagawa 761-0793, Japan.
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91
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Muccioli GG, Sia A, Muchowski PJ, Stella N. Genetic manipulation of palmitoylethanolamide production and inactivation in Saccharomyces cerevisiae. PLoS One 2009; 4:e5942. [PMID: 19529773 PMCID: PMC2691958 DOI: 10.1371/journal.pone.0005942] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 05/21/2009] [Indexed: 12/01/2022] Open
Abstract
Background Lipids can act as signaling molecules, activating intracellular and membrane-associated receptors to regulate physiological functions. To understand how a newly discovered signaling lipid functions, it is necessary to identify and characterize the enzymes involved in their production and inactivation. The signaling lipid N-palmitoylethanolamine (PEA) is known to activate intracellular and membrane-associated receptors and regulate physiological functions, but little is known about the enzymes involved in its production and inactivation. Principal Findings Here we show that Saccharomyces cerevisiae produce and inactivate PEA, suggesting that genetic manipulations of this lower eukaryote may be used to identify the enzymes involved in PEA metabolism. Accordingly, using single gene deletion mutants, we identified yeast genes that control PEA metabolism, including SPO14 (a yeast homologue of the mammalian phospholipase D) that controls PEA production and YJU3 (a yeast homologue of the mammalian monoacylglycerol lipase) that controls PEA inactivation. We also found that PEA metabolism is affected by heterologous expression of two mammalian proteins involved in neurodegenerative diseases, namely huntingtin and α-synuclein. Significance Together these findings show that forward and reverse genetics in S. cerevisiae can be used to identify proteins involved in PEA production and inactivation, and suggest that mutated proteins causing neurodegenerative diseases might affect the metabolism of this important signaling lipid.
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Affiliation(s)
- Giulio G. Muccioli
- Department of Pharmacology, University of Washington, Seattle, Washington, United States of America
- Louvain Drug Research Institute, Bioanalysis and Pharmacology of Bioactive Lipids Laboratory, Chemical and Physico-chemical Analysis of Drugs Unit, UCL-CHAM (7230), Université catholique de Louvain, Bruxelles, Belgium
| | - Angela Sia
- Gladstone Institute of Neurological Disease and Departments of Biochemistry and Biophysics, and Neurology, University of California San Francisco, San Francisco, California, United States of America
| | - Paul J. Muchowski
- Gladstone Institute of Neurological Disease and Departments of Biochemistry and Biophysics, and Neurology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (PJM); (NS)
| | - Nephi Stella
- Department of Pharmacology, University of Washington, Seattle, Washington, United States of America
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States of America
- * E-mail: (PJM); (NS)
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92
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Hwang J, Adamson C, Butler D, Janero DR, Makriyannis A, Bahr BA. Enhancement of endocannabinoid signaling by fatty acid amide hydrolase inhibition: a neuroprotective therapeutic modality. Life Sci 2009; 86:615-23. [PMID: 19527737 DOI: 10.1016/j.lfs.2009.06.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 05/28/2009] [Accepted: 06/03/2009] [Indexed: 12/31/2022]
Abstract
AIMS This review posits that fatty acid amide hydrolase (FAAH) inhibition has therapeutic potential against neuropathological states including traumatic brain injury; Alzheimer's, Huntington's, and Parkinson's diseases; and stroke. MAIN METHODS This proposition is supported by data from numerous in vitro and in vivo experiments establishing metabolic and pharmacological contexts for the neuroprotective role of the endogenous cannabinoid ("endocannabinoid") system and selective FAAH inhibitors. KEY FINDINGS The systems biology of endocannabinoid signaling involves two main cannabinoid receptors, the principal endocannabinoid lipid mediators N-arachidonoylethanolamine ("anandamide") (AEA) and 2-arachidonoyl glycerol (2-AG), related metabolites, and the proteins involved in endocannabinoid biosynthesis, biotransformation, and transit. The endocannabinoid system is capable of activating distinct signaling pathways on-demand in response to pathogenic events or stimuli, thereby enhancing cell survival and promoting tissue repair. Accumulating data suggest that endocannabinoid system modulation at discrete targets is a promising pharmacotherapeutic strategy for treating various medical conditions. In particular, neuronal injury activates cannabinoid signaling in the central nervous system as an intrinsic neuroprotective response. Indirect potentiation of this salutary response through pharmacological inhibition of FAAH, an endocannabinoid-deactivating enzyme, and consequent activation of signaling pathways downstream from cannabinoid receptors have been shown to promote neuronal maintenance and function. SIGNIFICANCE This therapeutic modality has the potential to offer site- and event-specific neuroprotection under conditions where endocannabinoids are being produced as part of a physiological protective mechanism. In contrast, direct application of cannabinoid receptor agonists to the central nervous system may activate CB receptors indiscriminately and invite unwanted psychotrophic effects.
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Affiliation(s)
- Jeannie Hwang
- Department of Pharmaceutical Sciences and the Neurosciences Program, University of Connecticut, Storrs, Connecticut, USA
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93
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Alexander SPH, Kendall DA. The life cycle of the endocannabinoids: formation and inactivation. Curr Top Behav Neurosci 2009; 1:3-35. [PMID: 21104378 DOI: 10.1007/978-3-540-88955-7_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this chapter, we summarise the current thinking about the nature of endocannabinoids. In describing the life cycle of these agents, we highlight the synthetic and catabolic enzymes suggested to be involved. For each of these, we provide a systematic analysis of information on sequence, subcellular and cellular distribution, as well as physiological and pharmacological substrates, enhancers and inhibitors, together with brief descriptions of the impact of manipulating enzyme levels through genetic mechanisms (dealt with in more detail in the chapter "Genetic Models of the Endocannabinoid System" by Monory and Lutz, this volume). In addition, we describe experiments investigating the stimulation of endocannabinoid synthesis and release in intact cell systems.
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Affiliation(s)
- Stephen P H Alexander
- School of Biomedical Sciences and Institute of Neuroscience, University of Nottingham Medical School, Queens Medical Centre, Nottingham, UK.
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94
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Malcher-Lopes R, Buzzi M. Glucocorticoid-regulated crosstalk between arachidonic acid and endocannabinoid biochemical pathways coordinates cognitive-, neuroimmune-, and energy homeostasis-related adaptations to stress. VITAMINS AND HORMONES 2009; 81:263-313. [PMID: 19647116 DOI: 10.1016/s0083-6729(09)81011-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Arachidonic acid and its derivatives constitute the major group of signaling molecules involved in the innate immune response and its communication with all cellular and systemic aspects involved on homeostasis maintenance. Glucocorticoids spread throughout the organism their influences over key enzymatic steps of the arachidonic acid biochemical pathways, leading, in the central nervous system, to a shift favoring the synthesis of anti-inflammatory endocannabinoids over proinflammatory metabolites, such as prostaglandins. This shift modifies local immune-inflammatory response and neuronal activity to ultimately coordinate cognitive, behavioral, neuroendocrine, neuroimmune, physiological, and metabolic adjustments to basal and stress conditions. In the hypothalamus, a reciprocal feedback between glucocorticoids and arachidonate-containing molecules provides a mechanism for homeostatic control. This neurochemical switch is susceptible to fine-tuning by neuropeptides, cytokines, and hormones, such as leptin and interleukin-1beta, assuring functional integration between energy homeostasis control and the immune/stress response.
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Affiliation(s)
- Renato Malcher-Lopes
- Laboratory of Mass Spectrometry, EMBRAPA-Center for Genetic Resources and Biotechnology, Brasília-DF, Brazil
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95
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Radiosynthesis, in vitro and in vivo evaluation of 123I-labeled anandamide analogues for mapping brain FAAH. Bioorg Med Chem 2008; 17:49-56. [PMID: 19054678 DOI: 10.1016/j.bmc.2008.11.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 10/31/2008] [Accepted: 11/09/2008] [Indexed: 11/21/2022]
Abstract
Fatty acid amide hydrolase (FAAH) is one of the main enzymes responsible for terminating the signaling of endocannabinoids, including anandamide. This paper is the first report of the synthesis, [123I]-labeling and in vitro and in vivo evaluation of anandamide analogues as potential metabolic trapping radioligands for in vivo evaluation of brain FAAH. N-(2-iodoethyl)linoleoylamide (2) and N-(2-iodoethyl)arachidonylamide (4) were synthesized with good yields (75% and 86%, respectively) in a two steps procedure starting from their respective acids. In vitro analyses, performed using recombinant rat FAAH and [3H]-anandamide, demonstrated interaction of 2 and 4 with FAAH (IC50 values of 5.78 microM and 3.14 microM, respectively). [123I]-2 and [123I]-4 were synthesized with radiochemical yields of 21% and 12%, respectively, and radiochemical purities were > 90%. Biodistribution studies in mice demonstrated brain uptake for both tracers (maximum values of 1.23%ID/g at 3 min pi for [123I]-2 and 0.58%ID/g at 10 min pi for [123I]-4). However, stability studies demonstrated the sensitivity of both tracers to dehalogenation.
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96
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Zvonok N, Pandarinathan L, Williams J, Johnston M, Karageorgos I, Janero DR, Krishnan SC, Makriyannis A. Covalent inhibitors of human monoacylglycerol lipase: ligand-assisted characterization of the catalytic site by mass spectrometry and mutational analysis. ACTA ACUST UNITED AC 2008; 15:854-62. [PMID: 18721756 DOI: 10.1016/j.chembiol.2008.06.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 06/09/2008] [Accepted: 06/23/2008] [Indexed: 11/29/2022]
Abstract
The active site of recombinant hexa-histidine-tagged human monoacylglycerol lipase (hMGL) is characterized by mass spectrometry using the inhibitors 5-((biphenyl-4-yl)methyl)-N,N-dimethyl-2H-tetrazole-2-carboxamide (AM6701), and N-arachidonylmaleimide (NAM) as probes. Carbamylation of Ser(129) by AM6701 in the putative hMGL catalytic triad demonstrates this residue's essential role in catalysis. Partial NAM alkylation of hMGL cysteine residues 215 and/or 249 was sufficient to achieve approximately 80% enzyme inhibition. Although Cys(215) and/or Cys(249) mutations to alanine(s) did not affect hMGL hydrolytic activity as compared with nonmutated hMGL, the C215A displayed heightened NAM sensitivity, whereas the C249A evidenced reduced NAM sensitivity. These data conclusively demonstrate a sulfhydryl-based mechanism for NAM inhibition of hMGL in which Cys(249) is of paramount importance. Identification of amino acids critical to the catalytic activity and pharmacological modulation of hMGL informs the design of selective MGL inhibitors as potential drugs.
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Affiliation(s)
- Nikolai Zvonok
- Center for Drug Discovery, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA
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97
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Magrioti V, Naxakis G, Hadjipavlou-Litina D, Makriyannis A, Kokotos G. A novel monoacylglycerol lipase inhibitor with analgesic and anti-inflammatory activity. Bioorg Med Chem Lett 2008; 18:5424-7. [PMID: 18819796 PMCID: PMC3712614 DOI: 10.1016/j.bmcl.2008.09.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 09/08/2008] [Accepted: 09/09/2008] [Indexed: 11/26/2022]
Abstract
A variety of long chain 1,2-diamines and related compounds were synthesized and tested for their activity on fatty acid amide hydrolase (FAAH) and monoacyglycerol lipase (MGL). (2S,9Z)-Octadec-9-ene-1,2-diamine selectively inhibits MGL (K(i) 21.8 microM) without significantly affecting FAAH. This compound exhibited interesting in vivo analgesic and anti-inflammatory properties, suggesting that selective inhibitors of MGL may be valuable novel agents for the treatment of inflammatory pain.
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Affiliation(s)
- Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
- Center for Drug Discovery, Northeastern University, 116 Mugar Hall, Boston, MA 02115, USA
| | - George Naxakis
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | | | - Alexandros Makriyannis
- Center for Drug Discovery, Northeastern University, 116 Mugar Hall, Boston, MA 02115, USA
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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98
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Placzek EA, Okamoto Y, Ueda N, Barker EL. Mechanisms for recycling and biosynthesis of endogenous cannabinoids anandamide and 2-arachidonylglycerol. J Neurochem 2008; 107:987-1000. [PMID: 18778304 DOI: 10.1111/j.1471-4159.2008.05659.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mechanisms of endogenous cannabinoid biosynthesis are not completely understood. We hypothesized that anandamide could be recycled by the cell to form new endocannabinoid molecules and released into the extracellular space. We determined that new endocannabinoids derived from exogenous anandamide or arachidonic acid were synthesized and released from RBL-2H3 cells in response to ionomycin. Treatment of RBL-2H3 cells with nystatin and progesterone, agents that disrupt organization of lipid raft/caveolae, resulted in the attenuation of anandamide and 2-arachidonyl glycerol synthesis and/or release in response to stimulation with ionomycin suggesting a role for these membrane microdomains in endocannabinoid biosynthesis. Furthermore, anandamide synthesis may be independent of N-acyl phosphatidylethanolamine phospholipase D as expression of the enzyme was not detected in RBL-2H3 cells. We also established that extracellular calcium is necessary for endocannabinoid biosynthesis because release of intracellular calcium stores alone does not promote endocannabinoid biosynthesis. Next, we examined the role of calcium as a 'switch' to activate the synthesis of anandamide and simultaneously reduce uptake. Indeed, [(3)H] anandamide uptake was reduced in the presence of calcium. Our findings suggest a mechanism indicative of calcium-modulated activation of anandamide synthesis and simultaneous termination of uptake.
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Affiliation(s)
- Ekaterina A Placzek
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47904, USA
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99
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Cabral GA, Griffin-Thomas L. Cannabinoids as therapeutic agents for ablating neuroinflammatory disease. Endocr Metab Immune Disord Drug Targets 2008; 8:159-72. [PMID: 18782012 PMCID: PMC2750822 DOI: 10.2174/187153008785700118] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cannabinoids have been reported to alter the activities of immune cells in vitro and in vivo. These compounds may serve as ideal agents for adjunct treatment of pathological processes that have a neuroinflammatory component. As highly lipophilic molecules, they readily access the brain. Furthermore, they have relatively low toxicity and can be engineered to selectively target cannabinoid receptors. To date, two cannabinoid receptors have been identified, characterized and designated CB(1) and CB(2). CB(1) appears to be constitutively expressed within the CNS while CB(2) apparently is induced during inflammation. The inducible nature of expression of CB(2) extends to microglia, the resident macrophages of the brain that play a critical role during early stages of inflammation in that compartment. Thus, the cannabinoid-cannabinoid receptor system may prove therapeutically manageable in ablating neuropathogenic disorders such as Alzheimer's disease, multiple sclerosis, amyotrophic lateral sclerosis, HIV encephalitis, closed head injury, and granulomatous amebic encephalitis.
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Affiliation(s)
- G A Cabral
- Department of Microbiology and Immunology, Virginia Commonwealth University, School of Medicine, 1101 E. Marshall Street, Richmond, Virginia 23298-0678 USA.
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100
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Endsley MP, Thill R, Choudhry I, Williams CL, Kajdacsy-Balla A, Campbell WB, Nithipatikom K. Expression and function of fatty acid amide hydrolase in prostate cancer. Int J Cancer 2008; 123:1318-26. [PMID: 18566995 DOI: 10.1002/ijc.23674] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The hydrolysis of endocannabinoids has profound effects on the function of the endocannabinoid signaling system in the regulation of prostate carcinoma cells. Prostate carcinoma cells exhibit a wide range of hydrolysis activity for 2-arachidonoylglycerol (2-AG), the major endocannabinoid. However, enzyme(s) responsible for 2-AG hydrolysis and their functions in prostate cancer have not been characterized. In this study, we demonstrated that fatty acid amide hydrolase (FAAH) was differentially expressed in normal and prostate carcinoma cells. In PC-3 cells, overexpression of FAAH resulted in increased FAAH protein, 2-AG hydrolysis, cell invasion and cell migration. Conversely, small-interfering RNA (siRNA) knockdown of FAAH in LNCaP cells decreased FAAH protein, 2-AG hydrolysis and cell invasion. Furthermore, CAY10401, a FAAH inhibitor, decreased cell invasion and it enhanced the reduction of invasion in FAAH siRNA-transfected LNCaP cells. Immunohistochemistry staining of commercial tissue microarrays (TMAs) demonstrated FAAH staining in 109 of 157 cores of prostate adenocarcinomas but weak staining in 1 of 8 cores of normal prostate tissues. These results suggest that FAAH regulates 2-AG hydrolysis and invasion of prostate carcinoma cells and is potentially involved in prostate tumorigenesis.
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Affiliation(s)
- Michael P Endsley
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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